1st Source (SRCE) 10-K 2024 FY Annual report

Exhibit 23

Consent of Independent Registered Public Accounting Firm

We consent to the incorporation by reference in the following Registration Statements:

Registration Statement No. 333-268217 on Form S-8 dated November 7, 2022

Registration Statement No. 333-255686 on Form S-8 dated April 30, 2021

Registration Statement No. 333-215910 on Form S-8 dated February 6, 2017

Registration Statement No. 333-207926 on Form S-3/A dated November 25, 2015

Registration Statement No. 333-207926 on Form S-3 dated November 10, 2015

Registration Statement No. 333-188266 on Form S-8 dated May 1, 2013

Registration Statement No. 333-173717 on Form S-8 dated April 25, 2011

Registration Statement No. 333-173715 on Form S-8 dated April 25, 2011

Registration Statement No. 333-173714 on Form S-8 dated April 25, 2011

Registration Statement No. 333-173713 on Form S-8 dated April 25, 2011

Registration Statement No. 333-101710 on Form S-8 dated December 6, 2002

Registration Statement No. 333-64314 on Form S-8 dated July 2, 2001

Registration Statement No. 333-26243 on Form S-8 dated April 30, 1997

Registration Statement No. 33-8840 on Form S-2 dated September 16, 1986

of our reports dated February 18, 2025, with respect to the consolidated financial statements of 1st Source Corporation and the effectiveness of internal control over financial reporting, included in this Annual Report on Form 10-K for the year ended December 31, 2024.

/s/ Forvis Mazars, LLP

Fort Wayne, Indiana

February 18, 2025